Ageing

Life expectancy in humans has raised surprisingly in the last decade and apparently it is still increasing by about 5 hours per day. This means that we wake up in the morning to a 29 hour day, but that we store 5 hours for later in our lives. (Well, it actually means that we wake up tomorrow to a 29 hour day, the day after tomorrow to a 34 hour day etc.) Unbelievable, ha?

Ageing has been a subject of extensive research. A part of scientific community believes that old age is associated with disease, but does not cause it. The other part tries to separate ageing and diseases and identify biological pathways responsible for ageing.

The following are the damages in cells that may contribute to ageing:

1. DNA damage (copying errors, telomere shortening, gene disruptions by viruses and transposons)
2. RNA damage (transcription errors, aberrant splicing)
3. Protein damage (misfolding, synthesis erros, impaired protein turnover, aberrant post-translational modifications)
4. Membrane damage (oxidation)
   

(Source: T. B. L. Kirkwood, Nature 451, 7th Feb 2008)